Reversing mechanism for steam-engines



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. EEVEESING MEGEANISM EOE STEAM ENGINES. No. 440,553.` Pat-entedNov. 11,1890.

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(No Model.)

H. PARNSWORTH. 'I REVERSING MECHANISM POR STEAM ENGINES.

4 sheets-sneet- 3.

Patented Nov. 11, 1890.

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` 4 Sheets- Sheet 4. H. T. FARNSWO'RTH. RBVERSING MECHANISM FOR STEAM ENGINES.' N0. 440,553.

Patented Nov. 11, 1890,

UNITED STATES PATENT OFFICE.

IIENRY T. FARNSVVORTH, OF MANCHESTER, ASSIGNOR OF TVO-THI'RDS TO JVTIIOMPSON BROFVN AND JOSEPH IV. BLANTON, BOTH OF RICHMOND,

VIRGINIA.

REVERSING MECHANISM FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters PatentV N0. 440,553, dated November 11, 1890.

Application iiled July 7, 1890. Serial No. 357,955. (No model.) l

To a/ZZ whom, it may concern:

Be itknown that I, HENRY T. FARNswoR'rH, a citizen ofthe United States, and a resident of Manchester,in the county of Chesterfield and State of Virginia, have invented certain new and useful Improvements in Reversing Mechanism for Steam or other Engines; and I do hereby declare that the following is a full, clear, and exact description of the invent-ion, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention has relation to improvements in reversing mechanism for steam or other engines.

l-Ieretofore in this class of devices, in order to successfully reverse the movements of the engine, it has been found necessary to employ two eccentrics to each valve or cylinder used in order to provide for the necessary lead to the engine, so as to permit of the ingress of the steam or air to the cylinder as the crank is moving toward the center.

It is one of the objects of my invention to dispense entirely with the employment of two eccentrics to each cylinder and at the same time secure the same result.

A further object is to provide means whereby the operator can control or change the direction of motion of the engine at any moment.

A further object is to provide a construction whereby the invention is adapted to be applied to any form of engine now in use, and with equal facility effect the function of running the saine in either direction.

A further object consists in providing means for regulating and adjusting the throw of the valve.

My invention has in view still further objects, which will appear from the following description, said invention consisting in the improved construction and combination of parts, as hereinafter more fully pointed out and described.

In the accompanying drawings, Figure 1 is a side elevation of an engine embodying my improvements, showing the cylinder in section and one of the slotted arms of the shifting bar broken away. Fig. 2 is a crosssection through the cylinder. Fig. 3 is a plan view, the top of the steam-chest being removed in order to show clearly the port-holes. Fig. 4E is a perspective detail view-of the upright plate or bracket which carries the slide-bar and shifting-bar. Fig. 5 is an edge View of the same. Fig. G is a side elevation of the shifting-bar and connecting-link. Fig. 7 is a perspective view of the swingingbar, looking from the side thereof from which projects the shafts, and also showing the arm which connects it to the slidebar. Fig. S is a perspective view of the fender which carries the swinging bar. Fig. 9 is a perspective view of the top of the valve. Fig. 10 is a similar view of the under side of the same. Fig. 11 is a detail perspective of the valve-hub and its adjustable lever. Fig. 12 is a detail view, in perspective, of the hook-block, showing the two sections thereof attached. Fig. 13 is a detail perspective of the slide-block which engages and works upon the hook-block. Fig. 14 is a detail perspective view of the block which works in the swinging bar, showing the slide-block connected thereto. Fig. 15 is a side elevation of the operating-lcver and connections, and Fig. 16 is a detail of the con-A necting-arm or turn-buckle.

Like letters of reference refer to like parts throughout the several views.

Referring to the drawings, the letter A indicates the bed-plate or base of the engine, to which is secured in the usual manner the cylinder B. A transverse shaft C is j ournaled in suitable bearings extending from the bedplate, and this shaft is provided with the usual pulley-'wheel D and end crank E, to which latter is attached the piston-rod F, provided with the usual piston-head G, working in the cylinder.

The letter C indicates the steam-chest, the lower half c thereof being preferably formed integral with the cylinder and provided with the ports c c and intermediate exhaust-port c2, the former communicating with the cylinder. The upper half c3 is provided with the usual inlet c4. Secured to opposite ends of the steam-chest are circular plates D D', said plates having an enlarged central portion upon their outer faces, and their inner faces provided with recesses d d, which form convenient packing-chambers.

Seated upon the valve-seat within the steamchest is a valve E', (shown clearly in Figs. 9 and 10,) and from which it will be seen that the top of the valve is of angular form, While the under side is concave. This valve is also provided with disks e2 and stems or journals e e', which pass through the circular plates D D', the packing in the chambers CZ CZ surrounding the same. It will be noticed that stem e is somewhat longer than its companion and is adapted to receive a hub F', said hub being provided with a slot f across its face, and also may be provided with an oil cup or hole (not shown) by which the journals can be oiled. In this slot fits a cranklever G', provided with elongated slots g g, into which work set-screws H H, by means of which the lever can be adjusted until the proper throw is given to the valve. The rear transverse shaft C has mounted thereon a cam-wheel I, and fitting around this cam is the circular portion of a rod J.

The letter K indicates a hook-block, which is preferably made of two similar sections, as illustrated in Fig. l2 of the drawings, said sections being provided with the forward hook portions 7c. The end of the rod J enters between the sections of this block, and is pivoted thereto by means of a transverse bolt L.

Secured to the` bed plate is an upright bracket M, said bracket provided with angular transversely-slotted ends m m and an intermediate boxing fm. The opposite side of the bracket is also provided with alongitudinal rib m2, which terminates at its lower end in a securing-flange m3. Working through the intermediate bearing or boxing of the bracket is a sliding bar N, said bar terminating at its rear end in a curved and vertical T-shaped extension fn, which the hook-block K is adapted to engage. A shifting-bar O is arranged to work within thel bracket M, and is formed with a vertical arm o, the opposite ends of which work through the slotted angular extensions of the bracket, and also provided wit-h lateral arms o 02, the former being somewhat longer than the latter, and both provided with elongated slots 03. A T-shaped sliding block P works through the slot in the shorter arm of the shifting-bar and receives the transverse bolt L, hereinbefore referred to, so as to be given a reciprocal movement when motion is imparted to the rod .I and hook-block connected thereto.

Pivotally secured to the forward end of the sliding bar N is a connecting-arm Q, said arm being preferably made in two pieces, as clearly shown in the drawings, so as to form an ordinary turn-buckle and thereby provide for the ready shortening or lengthening of the connection. The device is also provided with an an gularbracket R, (shown clearly in Fig. 8,) one end of which is secured to the side and top of the engine-frame and the other end to the back of the upright bracket M. At the angle of this bracket R is formed a bearing r,which receives a shaft S, and may also be formed with oil cups or apertures r to afford lubrication for shaft S. This latter connects with the center of a swinging bar T, which is formed on its opposite face with a wedgeshaped recess i. rlhe lower end of the swinging bar articulates with theforward end of the turn-buckle Q.

The letter U indicates a T- shaped slideblock, which works through the elongated slot of the longer arm of the shifting-bar O, and is provided on one end with a pin V, which passes through the slot and enters a wedge-shaped block W, which works in the correspondingrecess of the swinging bar T. The forward end of the sliding block is also provided with-a pin X, which passes through the rear end of a connecting rod or pitman Y, the forward end of said pitman in turn being pivotally secured to the adjustable crank-lever G.

It will be seen from the description of the foregoing elements that a complete connection is attained from the lever Gto the eccentric upon the rear transverse shaft.

Secured to the shifting-bar O is an arm Z, to which is pivoted the end of a hand-lever A2, said hand-lever being suitablyfulcrumed in a bifurcated standard B2, secured to the bed-plate. The free end of this hand-lever passes through a slot in a segmental notched bar C2, and is also provided with a springactuated pawl D2, adapted to engage the notches of the bar. This lever of course effects the function of raising and lowering the shifting-bar O. I wish to be understood, however, as not limiting myself to the particular construction of this feature of my device, as it is obvious that other forms may be used to accomplish the same purpose. When the valve hereinbefore referred to is placed upon its seat and the packing properly adj usted, the circular end plates D D are placed in position and screwed tightly tb the ends of the chest, so as to afford no chance for air to escape.

The drawings illustrate the valve in aposition to partly open the port farthest from the crank. In this position it is letting the air or steam into the cylinder at the end farthest from the crank-shaft, which would cause the shaft to revolve or turn from the cylinder, and as the shaft thus turns the valve continues to open until the crank assumes a perpendicular position. Then it begins to recede from this position, and as it thus reced'es the valve which before had been moving in the same direction as the shaft begins to move in the opposite direction thereto and close up the port which before was open and open the opposite port or the one nearest the crank, the change in the direction of the movement IOO IIO

of the valve being occasioned by the eccentric and eccentric arm. Again, assuming that the valve and connections are in t-he positions illustrated in the drawings, suppose the handlever is lowered, as illustrated by dotted lines in the drawings. When thus lowered,the shifting-bar will be elevated and the block WV raised to the upper end of the swinging bar T, and the hook-block K would be at the upper end of the curved extension of the sliding bar N. By this move of the parts the valve would be changed so as to allow a smallopening in the port c nearest the crank, and would consequently allow the air or steam to be entering that end of the cylinder, which would cause the crank to move toward the cylinder, or eX- actly reverse to its movement when the shifting-bar is lowered, as first explained. By thus moving the cylinder the valve would soon close that port the same way as explained in regard to the closing ofthe opposite port when the shifting-baris down-*that is, by the action of the eccentric after the crank has left its perpendicular position. With the closing of this port of course the opposite port c', or the one farthest from the crank, begins to open.

From the foregoing explanation it will be readily understood that while the hand-lever is down, as shown by dotted lines in the drawings, Fig. l5, the engine will run in the direction indicated by the arrow ct, Fig. 3, while when the hand-leveris raised the engine will run in the direction indicated by the arrow b, same figure. With my device, therefore,I

lobtain two opposite movements of the crank,

or the same result as is obtained by having two eccentric wheels for each cylinder, as is necessary with the old system. It will also be noticed that by throwing the shifting-bar up and down several results are obtained, as follows: When the bar is down, as shown in the drawings, there is a direct line of connection from the eccentric wheel to the valve or adjustable lever G, and said adjustable lever moves in the same direction as the eccentric rod or arm J. If, however, the shifting-bar is raised only half-way, or in a position to bring the block W over the center of the swinging bar T and the hook-,block K to the middle of the curved extension of the slidingbarN, the valve will stand still exactly on the center, having both ports shut,but the swinging bar and all other parts can continue to move without Vdoing any damage. On the other hand,if the shifting-bar is raised up to its full extent by lowering the hand-lever, then the swinging bar and all other parts move together, as usual, but the pitman Y, sliding block U, and lever G all move in opposite directions to the rest of the connections. It therefore follows from the above that by shifting the block W we change the motion of the valve, while by shifting the position of the hook-block we change the lead to the valve. For instance, to raise the block lV to the upper end of the swinging bar and leave the hook-block in the position illustrated in the drawings, the valve would have no lead; or, in other words, the steam would not be let into the cylinder until the pistonhead had moved away from the end of the cylinder, and the same result would follow in case the block W were left to remain at the place shown in the drawings, and the hookblock raised to the upper end of the curved extension of the sliding bar. By shifting both at thesame time, however, and in the same direction, the proper result is obt-ained.

It will be further noticed that when the shifter is brought to the half-way point of the traveling distance the wedge-shaped block W is brought right over the center of the swinging bar, and while there the swinging bar may be moving, but the valve stands still. By shifting the connections so as to raise the block W a little above the middle of the swinging bar a short stroke is given to the valve, by which only a small amount of air or steam will be lett in the cylinder, which will move the crank, as shown by the arrow b. By raising the block still higher there will be more stroke given to the valve and more air or steam consequently left in the cylinder. This motion of the valve can be increased until it opens full. By moving the block W downward the same throw will be given to the valve and the same results obtained, except that the engine will run in the other direction, as indicated by the arrow a..

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

l. The combination,with a cylinder, a steamchest provided with the usual ports, and an oscillating valve provided with stems and circular disks, of the end circular plates provided with a central enlargement upon their outer faces and a central concavity upon their inner faces to form packing-chambers, substantially as described.

2. The combination of a cylinder, a steamchest provided with the ports communicating lwith the cylinder and with an intermediate exhaust-port, a valve having its upper surface angular and its under surface concave and provided with end journals, and circular plates fitting over the ends of the steam-chest provided with central apertures through which the journals pass, and also provided upon their inner face with a concavity to receive the packing which surrounds the journals, substantially as set forth.

3. The combination, with a cylinder and steam-chest, of a valve provided with stems or journals passing through said steam-chest, and an adjustable lever or arm secured to one of the end journals for regulating the throw of the valve, substantially as set forth.

'4. The combination, with a cylinder and steam-chest, of a valve provided with stems or journals passing through said steam-chest, a hub mounted upon one of the end journals provided with a groove across its face, a lever IOO IIO

or arm seated in said groove and provided with elongated slots, and set-screws working in said slots, substantially as set forth.

5. In a reversing mechanism for engines, the combination of a cylinder, steam-chest, and valve, a crank-shaft for actuating the piston-rod, said shaft having a cam-wheel mounted thereon, a rod connecting with said cam, a hook-block pivotally connected to the forward end of the rod, said block being formed in two sections having forward hooked portions, a sliding bar having its rear end provided with a curved T-shaped extension which the hook-block engages, and connections between the forward end of this bar and the valve, substantially as set forth.

6. In a reversing mechanism for engines, the combination of a cylinder, steam-chest, and valve, a crank-shaft for actuating the piston-rod, said shaft having a cam-wheel mounted thereon, a rod connecting with said cam, a hook-block pivotally connected to the forward end of said rod, a bracket having a central boxing and end slotted extensions, a sliding bar working through the central boxing and provided at its rear end with a curved T- shaped extension which the hook-block engages, a shifting-frame consisting of two oppositelyextending horizontal slotted arms and a vertical arm working through the slots of the end extensions of the bracket, a T- shaped sliding block working through the slot of the rearwardly-extending member of the shifting-frame and connected to the hookblock, a swinging bar provided with a wedgeshaped groove, a turn-buckle pivotally connectingthe sliding bar with said swinging bar, a T-shaped sliding block workingin the slot of the forwardly-extendin g arm of the reversingframe, a wedge-shaped block secured thereto and working in the groove of the swinging bar, a pitman pivotally connecting the valvestem with the sliding block, and means for frame and connected to the hook-block, aA

bracket provided at its angle with a circular bearing,aswinging bar provided vvitha wedgeshaped groove and a laterally-extending shaft which passes through the bearing of the bracket, a turn-buckle connection between the sliding bar and swinging bar, a T-shaped sliding block working in the slot of the forwardly-extending arm of the reversing-frame, a wedge-shaped block secured thereto and working in the groove of the swinging bar, a pitman pivotally connecting the valve-stem with the sliding block, and means for elevating or lowering the reversing-frame, substantially as set forth.

S. In a reversing mechanism for engines, the combination, with a reversing-frame, of a fulcrulned lever pivotally connected thereto, said lever provided at its free end with a slot, a spring-actuated dog within said slot, and a notched segment provided with an elongated slot, substantially as set forth.

In testimony thatI claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.

HENRY T. FARNSWORTH.

W'itnesses:

J. THOMPSON BROWN, LE ROY E. BROWN. 

